Rents are at the highest level for more than a decade as house prices stretch beyond the means of would-be buyers, according to new research.

The findings from nationwide estate agency and lettings group Sequence show average rents hitting an 11-year high of £779 – a 4 per cent rise during August alone and an 11 per cent year on year increase.

The price hikes have been exacerbated by a shortage of supply and, in London, the problem is even more acute with rents up nearly double the national average to £1,465 and the average length of tenancy increased from 12 to 18 months as renters are priced out of the sales market, the report said. Head of lettings Stephen Nation warned: “If supply continues to be outstripped by demand, we will see further significant rent rises.”

The pressure on the rental market has also triggered a fresh surge in buy-to-let investing. The latest Council of Mortgage Lenders figures showed 15,200 buy-to-let loans worth £2bn advanced in July – up 11 per cent in a single month.